Embodiments of the present invention relate generally to assemblies and methods for preparing, analyzing, and detecting acid-fast bacilli with sputum smear microscopy. Effective analysis of microscopic images is essential in pathology. In low-income and developing countries, access to expensive microscopy methods and apparatuses is limited. Accordingly, direct microscopy from an unprocessed sputum smear is a primary method for detecting acid-fast bacilli when diagnosing a patient with pulmonary tuberculosis. Direct sputum smear microscopy can be an inexpensive and efficient method for diagnosing a patient with pulmonary tuberculosis, but has inherent drawbacks, such as low and variable sensitivity. Poor sensitivity may be attributed to the variable quality of the testing methods, inadequate sample sizes, unavailability of necessary equipment or supplies, and/or overworked and/or undertrained technicians. A need exists for a system and method for detecting acid-fast bacilli that is more efficient and inexpensive while being accurate and easily performed without specialized training.